div.overflow_1 {
  width: 300px;
  height: 100px;
  border: 1px solid brown;
  overflow: hidden;
}
div.overflow_2 {
  width: 100px;
  height: 50px;
  border: 1px dashed rebeccapurple;
  font-size: 200%;
  overflow: auto;
}
.box {
  width: 400px;
  height: 50px;
  border: 3px solid green;
  margin-top: 10px;
  background-color: blue;
}
.pos_static {
  position: static;
}
.pos_relative {
  background-color: green;
  position: relative;
  left: 10px;
  top: 20px;
  z-index: -10;
}
.pos_fixed {
  background-color: royalblue;
  position: fixed;
  top: 0;
  right: 0;
}
.pos_absolute {
  background-color: brown;
  position: absolute;
  top: 100px;
  left: 200px;
}
.menu:hover + .pos_absolute_menu {
  display: block;
}
.pos_absolute_menu {
  display: none;
  background-color: pink;
  position: absolute;
  top: 46px;
  left: 0px;
}
.pos_sticky{
  position: sticky;
  position: -webkit-sticky;
  background-color: orange;
  bottom: 100px;
  margin-left: 500px;
}
.box_float {
  float: left;
  background-color:red;
  margin-left: 20px;
}
.bfd {
  clear: both;
}
li {
  float: left;
  width: 100px;
  border: 1px solid black;
}